50 Gallon Tank Please help, lost half of my beloved guppies to a severe drug-resistant parasite, out of options

Hi everybody, everyone on other sites has run out of ideas. I'm really hoping one of you knows something I don't.

It all started a few months ago when a guppy came in with a parasite. This presented as white stringy poop, bloating and unstable swimming, after about two months it progressed to lethargy and death. At the time I thought it was constipation so hadn't realised anything was wrong.




Then it spread to another guppy. And another, and another. And much more aggressive this time too, typically kills within a week of the white stringy poop appearing. I've now lost 6 of my beloved guppies to this, every single treatment regimen has failed, and I fear I will lose all of them. I've tried the following when isolating (different guppies, not all at once):

1. Individually tried flubendazole, levamisole, and praziquantel treatment for 7 days
2. Tried all three medications in combination
3. Tried anti-internal bacteria, aquarium salt, and assorted other medications
4. Increased temperature to 28*C
5. Also tried dosing the main tank with flubendazole or levamisole to prevent further infections

Nothing worked, all but one died in exactly the same way, and it didn't stop the chain of transmission. After about 4 days of treatment, all but one of the guppies became lethargic, bloated, and died with gills wide open. The only one that didn't appeared to beat the illness (flubendazole only) - began passing normal poop again and was re-introduced to the main tank, but pineconed and died two days after re-introduction to the main tank. Cause of death looked more like a bacterial infection to me.

Below is a 320X microscopy of the white stringy poop. The only thing I can find consistently in all of these samples that looks possibly pathogenic is these egg-like things where the arrow is pointing to. I'm not sure whether or not these are normal, haven't tested normal guppy poop yet. No other signs of infection in the poop.




The only other thing to note is (a) this is affecting exclusively guppies, and (b) so far it has only killed the older (6-12 months) guppies. No younger guppies have shown symptoms.

If anyone could throw me a bone here I'd really appreciate it. Water parameters are all excellent, tank is heated and filtered @ 26*C.

And to add insult to injury... another guppy is now infected. I'm debating whether to just euthanise.

 

Hello, and welcome to Fishlore!

I am very sorry for your losses. Internal parasites are very contagious and it's advised to quarantine the first victim, although that information is useless to you right now. Internal parasites are a tough one to deal with.

A201 is our fish disease guru and I'm sure he will know how to help you. Other members will also have some input as well.

Sorry.

: (

 

Thanks alvinn.

I've attached a photo of the newly deceased guppy below. There are streaks of red to the left hand side. Does this look like anything to anyone?

Spoiler

Also just found another guppy dead, but I believe the cause is unrelated. He had a tear in his tail and it looks like it may have gone septic.

 

Sounds like you are having a rough time with your guppies....can you copy/paste and fill this template in please so that everyone can have some background on your aquarium, maintenance and water quality etc

https://www.fishlore.com/aquariumfishforum/threads/aquatic-emergency-template.376562/

Thank you

 

Tank
What is the water volume of the tank?: 180L
How long has the tank been running?: 9 months
Does it have a filter?: Yes
Does it have a heater?: Yes
What is the water temperature?: 26*C
What is the entire stocking of this tank? 2 female betta, 7 kuhli loach, 20 otocinclus, 3 neon tetra, originally 12 guppies now down to 5

Maintenance
How often do you change the water? Weekly
How much of the water do you change? 50%
What do you use to treat your water? Fluval dechlorinator
Do you vacuum the substrate or just the water? Just water

*Parameters - Very Important
Did you cycle your tank before adding fish? Yes
What do you use to test the water? API droplet test kit
What are your parameters? We need to know the exact numbers, not just “fine” or “safe”.
Ammonia: 0
Nitrite: 0
Nitrate: 10
pH: 7.5

Feeding
How often do you feed your fish? Daily
How much do you feed your fish? Pinch
What brand of food do you feed your fish? Varied, King British, Fluval, Tetra
Do you feed frozen or freeze-dried foods? No

Illness & Symptoms
How long have you had this fish? Sick guppies are average 9 months old
How long ago did you first notice these symptoms? Two months ago
In a few words, can you explain the symptoms? White stringy poop, bloating, unstable swimming, followed by lethargy and death within a week
Have you started any treatment for the illness? Pretty much every single one available, see OP
Was your fish physically ill or injured upon purchase? One with parasite was yes, see OP
How has its behavior and appearance changed, if at all? See above

Explain your emergency situation in detail. See OP

 

Otos, Kulis & Neon Tetras are relatively fragile species & are usually the first to go when an outbreak occurs. Evidently the problem isn't readily contagious to the tankmates.
On the other hand, Guppies are usually a little more durable as long as the water parameters are suitable; hard water w/ elevated PH.
The OP noted the failure of several deworming meds.
If I understand correctly, the guppies apparently were fine up until approx. six months, then came the decline in health. Were they reproducing?
I suggest buying a new batch of Guppies from another vendor or local breeder. Plenty of weak strains out there.
No sense blindly nuking the tank with meds. They haven't worked anyway. The problem might simply be genetics, or even a water chemistry issue.

 

Thanks A201.

Two more dead guppies today. Most of these guppies are from different vendors. Nothing apparent wrong with the water chemistry and no other species are affected.

Anyway, three left, one newly sick. I've just accepted they're probably all going to be dead by next week, probably just going to sell the tank to be honest. It's just hopeless.

 

Before scrapping the tank, maybe take it in another direction. Since you apparently are interested in livebearers, maybe try Swordtails or Mollies.

 

I'm just worried exactly the same thing is going to happen to be honest. Without knowing what this disease is I have no idea whether the pathogen/eggs of pathogen are going to remain in the tank unless I sterilise it in some way.

 

What ever is going on, its apparently not affecting the tankmates. Species like Swordtails are beautiful and IMO, a much more durable species than Guppies.

 

Thanks A201. I've decided I'm going to rebuild the tank instead of selling up. I'm going to get guppies again as I love watching these little things go.

What do you think is the best course of action - I'm thinking wait two months before getting any more to reduce the risk of re-emergence? Do you think a UV steriliser is a good idea?

Amazingly the last sick guppy appears to have recovered, making it the first and only one to survive this disease. The two little babies have never shown any symptoms at all, perhaps young and spritely enough to fight it off.

 

Buy from a different seller this time.

 

Unfortunately nearly all of these little fellas were from different sellers so I'm not sure it's a genetic/inbreeding vulnerability. I know which guppy brought the disease in though so will be avoiding that seller.

 

Unfortunately down to our last guppy now, we had two very young guppies we thought had gotten away with it and one of them passed away suddenly. This one has developed a bit of an odd bloating/curve in his back and a tattered tail. Also staying near the top all the time. He also has the white stringy poop occasionally.

Any ideas on this one? I'm not sure it's the same pathogen as it was before. We're currently treating him with chloramine-T, which I believe is the last remaining drug available in the UK that we haven't tried yet

 

The OP noted the failure of several deworming meds.

Which, combined with the microscope pics, tells me the likelihood of protozoans as internal parasites is high. @OP: Able to get Sera products? If so get Sera Med Flagellol. Only if that doesn't work either one can speak of a resistant parasite.

On the other hand, Guppies are usually a little more durable as long as the water parameters are suitable; hard water w/ elevated PH.

OP says they're in the UK. In Europe Guppies from the regular trade are the same resilience category as farmbred rams and cheap bettas: Look at them funny and they drop dead.

I'm not sure it's the same pathogen as it was before. We're currently treating him with chloramine-T, which I believe is the last remaining drug available in the UK that we haven't tried yet

Do a big waterchange, chloramine-T is a tank nuke. You still have quite a list of meds to go through, but I am very positive the one I named above is going to help. I also would ask myself after that amount of meds, whether it is still worth it. Because the surviving fish will likely have taken some permanent damage to their inner organs.

 

Which, combined with the microscope pics, tells me the likelihood of protozoans as internal parasites is high. @OP: Able to get Sera products? If so get Sera Med Flagellol. Only if that doesn't work either one can speak of a resistant parasite.



OP says they're in the UK. In Europe Guppies from the regular trade are the same resilience category as farmbred rams and cheap bettas: Look at them funny and they drop dead.



Do a big waterchange, chloramine-T is a tank nuke. You still have quite a list of meds to go through, but I am very positive the one I named above is going to help. I also would ask myself after that amount of meds, whether it is still worth it. Because the surviving fish will likely have taken some permanent damage to their inner organs.

Thanks very much for the reply. Protozoans crossed my mind as well. I might put some flagellol on order, though I suspect it's already too late for this last one.

They're in an isolation bucket with chloramine-T right now so the tank is safe. I'm just trying as a ditch attempt really. I think you're probably right about there being permanent damage, the only one of the guppies that appeared to recover after treatment pineconed and died shortly after.

I've bought a UV steriliser and I think I'm just going to run it in the tank for a few months before I get any more livestock again.

 

As soon as you know it's internal parasites there are three possibilities in the european trade (incl. UK): Worms (mostly Nematodes and Camallanus), Protozoans (incl. Hexamita and Ciliates) or Amoeba. The latter is quite hard to treat as there is no specialized med against that but one can improvise. I would have to look up the combination people have reported to work.
Anyhow, I only see protozoans on the microsopies, so Flagellol is the correct answer. I would actually treat the whole tank with that, as they are quite contagious.

Good call to treat with C-T in isolation! And yes, sounds like kidney failure.

Even if you don't use the UV, you should be save to stock up fish after 4-6 weeks without any losses.

 

I've ordered some Flagellol just in case there are any future outbreaks. Regardless, thank you very much for the responses - it's nice to have an ID on this even despite having lost everything. It was so frustrating losing all of my livestock with absolutely no explanation why.

 

You are extremely lucky a diagnosis in hindsight was even possible (mostly because you fotographed the fish while still alive and made some microscopy. 99% of cases asking after the fish died end up being unsolved. And the rest most often is only "likely bacterial infection", "likely inner parasites" but nothing more conclusive.

 

Hello again everyone

I've got a bit of a dilemma here. Of the two remaining guppies the little young'un unfortunately passed away a couple weeks back. However, the last one remaining appears to be the only survivor of this unfortunate disease. He's still alive a few weeks after showing symptoms.

Problem is he now spends his entire life at the top of the tank, seemingly gasping for air. Either he is still fighting the infection, or it has crippled him and he's just going to struggle the rest of his life.

The Sera Med Flagellol finally arrived from France yesterday. I'm in two minds whether to treat this little guy or euthanise him. My main worry is that if he is still fighting infection then he could still be a reservoir that would infect any new guppies I add.

What would you all do?

 

My main worry is that if he is still fighting infection then he could still be a reservoir that would infect any new guppies I add.

Thought absolutely correct.

I would likely put it down. Then run the tank without fish for two weeks (usually this kills all parasites that can't use other animals like snails as hosts, as without a host the parasites are dine for) do some big waterchanges in the meantime and keep the med for future cases. That parasite is really common, so there will be more in the future.

 

I would have suggested fenbendazole as opposed to flubendazole. Fenbendazole normally found in dog dewormer like panacur c. It will kill most internal parasites, all worms and flukes. I have used it on many types of fish as soon as i see stringy poop or flashing and ever time they are healthy within 24 hours.

 

Thanks both.

I've decided to have a ditch attempt to treat the last guppy with sera med flagellol. It's been 24 hours and he does look a bit more perky, not just living at the top anymore. Fingers crossed this last one will survive.

 

Unfortunately the sera med didn't work - the last remaining guppy took a turn for the worse today, started with the white stringy poop again and red patch around anus that looked like the beginning of sepsis. I decided to euthanise. Does anyone have any other med suggestions? Hopefully after UV'ing for a month the tank should be safe, but it irks me that this has had a 100% kill rate and no medication I've tried has done anything.

 

Update (hopefully final update) - I ran UV in the main tank for two weeks after the last guppy was removed, then added more guppies. They've been in the tank a week now and touch wood nothing looks sick. Hopefully I have seen the last of it.